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Another sync tragedy


whatalob
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I did the sound for this short film shot on 16mm running at 24 fps. I set my recorder at 48KHz and 24 (apart from the first few shots, where it was left at 25 by mistake)

there was no tc jamming, a clapperboard was used for all shots.

Now a few months later I am told they can't sync none of the audio. It has already been transferred to beta and then to digital for Avid mxf. No syncing done at any of those stages. Now if I understand correctly the material is at 25 fps? I didn't even get a clear answer

Is the audio to blame here? I know that there should have been guidelines by post as to audio framerate settings but there weren't. Just wondering what I can do from my side perhaps in TC restamping or anything else. At leas to fix those shots that were not stamped at 24, if indeed this is the correct setting in the first place.

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Hello, where have you been ??

" film shot on 16mm running at 24 fps.(crystal controlled ??) I set my recorder at 48KHz and 24 (apart from the first few shots, where it was left at 25 by mistake)

sounds like time code is really not even involved here...not really,

This issue was resolved over 25 years ago...(and without timecode)...

when they "transferred to beta" film, shot at 24.00, was converted to 29.97 FPS video rate, that is it was changed from 24 FPS to 30 FPS (called 3:2), and then slowed down by .1% this is a speed change, TC is not required or involved.

with the images now going .1% slower, the sound gets quickly out of sync, each take with the VDO images; the sound, no matter what frame rate you had set in your recorder) needs to be pulled (slowed)down .1% to match the VDO, and you need to do some searching and learning. As discussed elsewhere, this is something you need to know about to command and deserve proper rates as a qualified and experienced production sound mixer.

OTOH, this is also something that the production should have known and applied; and the phrase that comes to mind is "workflow test", --and of course a real production would have known about it on the morning after the first day since they didn't test their workflow; IOW, you are dealing with amateurs. If your audio had also been sent to the telecine, it would have also been slowed down to match the pictures as part of the process..

Edited by studiomprd
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I am not get into details on why I posted like I did. I am in a dispute with an editor who as a benefit of a doubt I give that he might know better and put the blame on me. I am aware of the above but needed some confirmation, was feeling insecure perhaps. This is not my main job but nevermind, you do help a bit.

Now is the pull down possible in avid or should it be done in a daw?

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Now a few months later I am told they can't sync none of the audio. It has already been transferred to beta and then to digital for Avid mxf. No syncing done at any of those stages. Now if I understand correctly the material is at 25 fps? I didn't even get a clear answer

Are you in the States or Europe?

If you are in a legacy-PAL country, they telecined the film to 25FPS, so they need to speed up the audio 4% to match the transfer.

If you are in a legacy-NTSC country, they telecined the film to 29.97FPS (most likely, although it could be 23.976). If that is the case, they need to slow down your audio .1% to match the transfer.

If they haven't done anything to your audio to match picture speed, it's their fault.

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Legacy-PAL here. Am I right that this 4% speed up is by pulling up in the tc stamp so it won't affect the actual pitch?

no. The Senator (oddly enough) gave you a very good, clear explanation about what happened. If you cannot grasp the concepts he has mentioned above, I strongly suggest you do some research and some reading before your next gig.

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They got themselves in all sorts of trouble by shooting 24 and telecining 25. It sounds like they did the telecine MOS so there was no sound to tell them they were out of sync (but didn't they notice that everyone onscreen was moving kind of fast?). It is a relatively simple matter to speed up your audio files by 4% anymore--you can do it in Audacity (freeware), save the result to a new file and then try to manually sync up the sound. The pitch will be higher since the audio file is now playing faster. You can experiment with pitch shifting the audio back down a bit if you want, but the actors will still be speaking faster than they were on the set--there is nothing to be done about that.

It's ok to ask questions, even about old issues like telecine.

philp

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Yep, what Phil said.

The answer is just to hire a Pro Tools guy to perform a varispeed, through trial and error, and find the precise speed that will lock up to the picture. It ain't rocket science, and it can be done. Once they know the exact speed, it should be consistent throughout the entire project, assuming the exact same setup was done every day (by camera and sound departments, and by the telecine post house).

I really, really hate it when people don't sync up as part of dailies. If they had been doing this from day 1, they would've known, "uh-oh... we got a problem!"

And this is not a mixer problem. If they didn't give Whatalob the precise specs, then they're guilty of not communicating correctly. Then again, I firmly believe in a "CYA" mode where you need to get a solid commitment -- preferably in writing, like in an email -- stating camera frame rate, timecode for picture, and (presumably) timecode for sound. And also who is responsible for providing timecode during production.

I have seen weird situations in post where we had to do double-pulldown or weird frame rates in order to get sound to sync up with picture (at 23.98 or 29.97 for American video), but it's not that hard to do. It's time-consuming if all the slates are wrong, but as long as dialogue is in sync, it's not that big a deal. Literally, an assistant editor could sync up every take of an entire picture in a week, and it's not an earth-shattering cost (like maybe a couple of thousand dollars). It's a mistake, but this is why shows should hire a post-production supervisor from day 1, to stop things like this from happening.

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thank you all for the enlightenment. it looks pretty bad. I am only trying to help out these people who have not done film before. Neither have I and I wish I knew more about it. I could have say its not my problem and and not make myself look silly, but I d rather help in getting the film done. Problem is the editing is happening miles away.

One more thing. What happens when the edit goes back on film to 24fps? What about if they decide to do a seperate sound edit before? There I assume it stays at 25?

thanks again.

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" these people who have not done film before. "

I'm not surprised...

" I am not get into details on why I posted like I did. "

well maybe you should have, as if you had told us more, then we could have perhaps answered better, more clearly, and more appropriately. for example if you had divulged your location (PAL area) that would have been quite important (and maybe even more confusing)., and at least earned you a bit of an excuse for not understanding the .1% speed change, and that it probably was not your issue anyway; then I would have seriously questioned." the first few shots, where it was left at 25 by mistake " instead, although that still would not have made things much better, either. What were these folks doing?? BTW, was the camera actually a sync-sound camera with crystal sync motor??

" What happens when the edit goes back on film to 24fps? "

"they" better do some workflow tests, as that will be slowing everything (back) down by 4%, a noticeable amount for both picture and sound.

" I am in a dispute with an editor who as a benefit of a doubt I give that he might know better and put the blame on me. "

ah, then its the "blame game"...

...or...

" I am only trying to help out these people "

...or...

" Is the audio to blame here? "

Actually there is plenty "blame" to go around for everyone. it apears it was the blind leading the blind as you didn't know what to do, and neither did they " these people who have not done film before. ", so of course they didn't tell you " Neither have I and I wish I knew more about it. " what to do... and none of you knew enough to even know what you didn't know so you could do a workflow test and figure it out before shooting the movie months ago!

" There I assume ... "

then you have not learned any lesson from this

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Senator Mike's somewhat halting and brusk manner is entirely on-target and appropriate here.

If you undertake something you know nothing about, the chances for issues to arise are great. If you undertake something you know nothing about in collaboration with others who know nothing about what they are doing, your chances for issues to arise are pretty well guaranteed.

Now that you've proven both of those statements to be true, it's time to learn from them.

Sync problems typically reflect on the sound team even if it wasn't sound that caused the issues. Look at it from their perspective, the picture looks okay, but when they go to add the sound, there are issues -- therefore, there are SOUND ISSUES. This isn't necessarily fair, but it's the way people think.

This is just part of the reason it's essential that the sound person know what they're doing. This is also why, if you want to avoid issues being blamed on the sound department, it's important to be proactive.

Prior to shooting, insist on a workflow test -- and make sure that camera knows what rate they're filming at, and why. This should not all be up to the sound department, as proper camera setup clearly falls under camera department duties, but if you don't take the initiative up front to make sure things are right, you're likely to receive the blame in the end when things go wrong.

If you don't know anything about time code, you shouldn't even try to use time code -- you're just bringing up more issues to blame on the sound department -- and in that instance it's justified, as it's your job to know what you're doing.

Clapper sticks are the most foolproof syncing method ever developed.

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Clapper sticks are the most foolproof syncing method ever developed.

Only if the speed is stable. Clappers won't do you any good with wild 1/4" tape or a camera that doesn't use crystal or AC sync.

The only foolproof syncing method is single-system... first production company I worked for still had an optical Auricon. Sounded horrible (particularly since they loved to use reversal film), but it sure held sync.

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as Jay Rose posted, while I was typing this...

Timecode actually has nothing to do with the problems being encountered, and its only role in this situation is as the crystal controlled source of stability of the double system audio recordings, which needs to be matched by a crystal control of the film camera.

" Clapper sticks are the most foolproof syncing method ever developed... "

for establishing a sync point (a place to lock the image to the sound); the other part of sync is image and sound staying together beyond the sync point. this requires both of the systems (image and sound) to be accurately advancing together; anything done that affects on of these two separate (though coordinated) systems, --speed changes-- must be appropriately applied to the other system.

Edited by studiomprd
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Only if the speed is stable. Clappers won't do you any good with wild 1/4" tape or a camera that doesn't use crystal or AC sync.

The only foolproof syncing method is single-system... first production company I worked for still had an optical Auricon. Sounded horrible (particularly since they loved to use reversal film), but it sure held sync.

As you know, most modern gear is solid in the speed department -- especially for narrative-feature-length takes..

I also considered single system when I made the statement, but recalled that there are cameras that have internal picture/sound drift -- so that's not guaranteed, either.

Clappers are one of the oldest -- but still most reliable -- sync methods.

Of course, clappers don't guarantee staying in sync, but neither does time code, which is what I was actually referencing the "clapper" comment to (the O.P.'s use of time code when he didn't understand it) -- nor, of course, does time code "lock" in time to the picture as it is only a stamp in the file's header.

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as Jay Rose posted, while I was typing this...

Timecode actually has nothing to do with the problems being encountered...

...

...and in the O.P.'s case only served to confuse the issue further. Hence my statement that he shouldn't have even been using it, since he didn't understand it.

I don't understand why you're arguing with me, Mike, since I'm agreeing with you. <g>

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Only if the speed is stable. Clappers won't do you any good with wild 1/4" tape or a camera that doesn't use crystal or AC sync.

The only foolproof syncing method is single-system... first production company I worked for still had an optical Auricon. Sounded horrible (particularly since they loved to use reversal film), but it sure held sync.

I managed to get an Auricon Cine-Voice to record optical out of sync--all you have to do is mis-thread it!

philp

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I can explain my self further if that would make people feel better.

I live in a place with limited cinema production. There is not even a film transfer lab around, hence the lack of workflow test. (plus many other usual factors)

My main line of business is in the studio recording music. I also do some location work for picture and it has always been with digital cameras, prosumer video or dslr.

I never had a sync problem before.

I have done a lot of research and have reached a level of getting good sound and solving most problems. I never had the luxury of a mentor though.

I don't know much about editing systems, and how those systems interpret the framerate stamp on an audio file. Ofcourse I know there is no actual framerate in audio and if you actual speed it up the pitch will change. My question regarded whether somehow the editing system uses the framerate stamp to interpret audio in a different way without affecting the actual speed. No that I thnk about it it does sound like nonsense.

I ve never jammed my recorder with another device, noone even demands it or knows how to do it.

I never said that I used TC to sync with the camera. The camera had no sound, it was an old 16mm arriflex that made lots of noise and messed with my dialogue anyway. the leather cover made no real difference

I wrote the OP like I know nothing because the people I talked, did confuse me and I wanted a clear answer myself.

I did get those answers mostly. But I also got confused a bit.

Does the framerate stamp in the audio file matter in cases where the sync is done manually with a clapper? This has to do with my lack of knowledge in picture editing systems.

If it does, would restamping do the trick?

How does it work that the sync happens in the transfer stage? I mean that a roll of film does not correspond to a bunch of audio files so how would it be done in the transfer lab as philp suggested?

What options are there when transferring to digital? Could the framerate have remain the same at 24?

If I had jammed to a TC device should I have used 23.98?

Forums like this have been very helpful many times and I appreciate it all. And while its not nice to be told off I also understand when people get angry at questions that lack basic understanding and show negligence. I 'd like to believe my case is not so bad, as my initial understanding when shooting this short is that, with the clapper no sync problems should come up. I had also discussed this with the dop and producer, when shooting. But when you get a phonecall with lots of info thrown at you that I have no perfect understanding you do get overwhelmed.

Its natural that you hollywood guys do know much better and its nice that you share the knowledge. thanks

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I managed to get an Auricon Cine-Voice to record optical out of sync--all you have to do is mis-thread it!

Heck, we've all seen projectionists do the same thing with optical prints!

(Some very large theaters used to do this intentionally, to delay the audio so it would work for the bulk of the audience.)

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Restamping will help vis a vis the Final Cut Pro feature/bug that makes it want to change the playback speed of audio files whose TC framerate stamp differs from the project rate as set in the edit system, but ONLY if the playback speed of the picture hasn't been changed in the course of the work so far (ie film transfer to video at what rate etc), AKA "pull down". Are your editors working in PAL?

Syncing sound to picture for a FILM shoot can happen either at the session where the film is transferred to video (telecine) or later in an edit system (like Final Cut) where the picture files transferred without sound have already been loaded. There are basic project technical questions to be answered though--like what fps the film was shot at, what rate it was transferred at, and what the project frame rate of the edit system is. In general, any more, if the audio (recorded digital) and the picture do not sync up for shortish takes (under 10 min) then the playback speed of either picture or sound has been changed. The good news is that it can all be fixed once you have this information.

philp

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=Does the framerate stamp in the audio file matter in cases where the sync is done manually with a clapper? This has to do with my lack of knowledge in picture editing systems. If it does, would restamping do the trick?
No, restamping will not help in this case because the film itself was transferred at a rate different than what it was shot. Assuming it was transferred at 23.98 (vs. 24), then the sound has to be pulled down by .1%. If they ran the film at 25fps -- which is not impossible in a 50Hz country -- then the sound might have to be pulled up 4%. Pro Tools is what I've generally used to solve pull-up/pull-down problems, but there are a bunch of ways to do it (hardware and software).

How does it work that the sync happens in the transfer stage? I mean that a roll of film does not correspond to a bunch of audio files so how would it be done in the transfer lab as philp suggested? What options are there when transferring to digital? Could the framerate have remain the same at 24? If I had jammed to a TC device should I have used 23.98?

Sync happens in the transfer stage with a sync generator: a precise crystal-controlled device that vibrates at a set frequency. Output signals -- both video and sound -- are generated so that every piece of equipment in the chain is precisely synchronized. Then and only then can you sync up picture and sound. Almost literally, the sync generator is like the sprocket holes in the edges of the film. WIthout that... it ain't gonna run at the right speed.

There are so many possible scenarios and solutions, I can't really provide any answers until you get all the basic info together: what speed was the camera running, how was the film transferred in telecine, what system was used for editing, how were the dailies files ingested, what session rate is the editor using, and so on. There are many, many ways to screw yourself in post.

Sadly, this is why producers (especially people doing low-budget indies and shorts) should get in touch with a post house or post supervisor prior to shooting a frame, to make sure their workflow is correct. If they're going about it the wrong way, it's best to ask first. One phone call could have solved all these problems. It also wouldn't hurt to ask here or on an editor's forum, to basically say: "we have a film we want to shoot. What are the typical settings for camera and sound in production and post that we should use so that the project will work?"

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" it was an old 16mm arriflex that made lots of noise :"

as I noted earlier,(what possible film camera they were using...needs to be matched by a crystal control of the film camera. ) this camera does not have a crystal controlled motor to keep it running precisely on speed for exact sync throughout a take (past the clap)... this is still another part of the puzzle that your wanna-bee moviemakers missed in their grand scheme.

this is all stuff that should have been found out before shooting the movie...

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" it was an old 16mm arriflex that made lots of noise :"

as I noted earlier,(what possible film camera they were using...needs to be matched by a crystal control of the film camera. ) this camera does not have a crystal controlled motor to keep it running precisely on speed for exact sync throughout a take (past the clap)... this is still another part of the puzzle that your wanna-bee moviemakers missed in their grand scheme.

this is all stuff that should have been found out before shooting the movie...

Yes, if it's an Arri S it will not keep sync. Find out the camera model. An SR will hold sync though.

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Doh, I hope it's not an Arri S. I used an Arri M while in film school, and those were rock-solid (and actually, not too noisy). The SR was a huge, gigantic improvement.

When crystal sync came out, it totally changed the world -- just not having to have the 60Hz connection to the Nagra was a big difference for me. I had one disastrous shoot while in college where the equipment rental company gave us a bad sync cable, and it gave me fits because the Nagra was basically running "wild" and not synced. Took days of tweaking in editing (the hard way, with splicers) to get it to work.

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well so far, I have been told that, the problem was in the lab that transferred the telecine beta to digital files. Now apparently the project is back on 24fps in avid (not 23.98) and will be edited as such. Apparently the tried to sync a few of the files with the 24 stamp and they all synced ok. So no drifting issue yet, but the real editing has not begun yet.

They also tried takes from the day where my recorder was set to 25, and there they could not sync. I know restamped one file to 24 and have sent it and am waiting for their response. I tried to get an exact explanation of all steps. (in other words what the hell exactly happened? was it 24->25->24 and why) but I did not get one.

I 'll keep you updated.

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